Yeo Jacob Z-Q, Rosentreter Judith A, Oakes Joanne M, Schulz Kai G, Eyre Bradley D
Centre for Coastal Biogeochemistry, Faculty of Science and Engineering, Southern Cross University, PO Box 157, East Lismore, NSW, 2480, Australia.
Nat Commun. 2024 May 10;15(1):3967. doi: 10.1038/s41467-024-48178-4.
Estuaries play an important role in connecting the global carbon cycle across the land-to-ocean continuum, but little is known about Australia's contribution to global CO emissions. Here we present an Australia-wide assessment, based on CO concentrations for 47 estuaries upscaled to 971 assessed Australian estuaries. We estimate total mean (±SE) estuary CO emissions of 8.67 ± 0.54 Tg CO-C yr, with tidal systems, lagoons, and small deltas contributing 94.4%, 3.1%, and 2.5%, respectively. Although higher disturbance increased water-air CO fluxes, its effect on total Australian estuarine CO emissions was small due to the large surface areas of low and moderately disturbed tidal systems. Mean water-air CO fluxes from Australian small deltas and tidal systems were higher than from global estuaries because of the dominance of macrotidal subtropical and tropical systems in Australia, which have higher emissions due to lateral inputs. We suggest that global estuarine CO emissions should be upscaled based on geomorphology, but should also consider land-use disturbance, and climate.
河口在连接陆地到海洋连续体的全球碳循环中发挥着重要作用，但对于澳大利亚对全球碳排放的贡献却知之甚少。在此，我们基于47个河口的二氧化碳浓度进行了全澳大利亚范围的评估，并将其扩展至971个经评估的澳大利亚河口。我们估计河口二氧化碳排放总量的平均值（±标准误差）为8.67±0.54太克碳/年，其中潮汐系统、泻湖和小型三角洲分别贡献了94.4%、3.1%和2.5%。尽管更高的干扰增加了水-气二氧化碳通量，但由于低干扰和中度干扰的潮汐系统表面积较大，其对澳大利亚河口二氧化碳排放总量的影响较小。由于澳大利亚的大潮差亚热带和热带系统占主导地位，其侧向输入导致排放量较高，因此澳大利亚小型三角洲和潮汐系统的平均水-气二氧化碳通量高于全球河口。我们建议，全球河口二氧化碳排放的评估应基于地貌学进行扩展，但也应考虑土地利用干扰和气候因素。
